What lies beneath Pterorhynchus: Is that a dewlap?

Pterorhynchus is a Middle Jurassic pterosaur that preservers soft tissue in the one and only known specimen. Of interest today is the soft tissue below the mandible (Fig. 1).Chris Collinson wrote to the DML: “The dewlap honestly looks more like a “feather” beard of sorts than a pelican pouch.”

Figure 1. Pterorhynchus dewlap. Is this a feathery beard? Has it been torn off of another part of the body? Does it even belong to this pterosaur? Is it a fish? Or a plant? Click to enlarge. By the way, this is about as far as I manipulate photos, increasing the contrast in the middle and traced on the right.

Some data deniers
were not happy when I added this ‘beard’ to my reconstruction of Pterorhynchus. Those workers thought I was ‘seeing things’ that are not there. Getting back to reality, several people have seen this structure (see above), so it is definitely there, but no one has defined what it is yet (that I know of).

If it is a secondary sexual trait like a wattle, dewlap or gular sac, then it would have added to aerodynamic drag, but might have been considered ‘sexy’ enough to be selected. Long-winged pterosaurs like Pterorhynchus, may not have been aerial speedsters, drag might not have been such a big problem.

If it is throat tissue torn away from the body, then it would match similar tissues preserved in other pterosaurs and fenestrasaurs. That’s my best guess.

If it is another portion of the pterosaur, I don’t see clues as to where it may go… but then I have not seen hi-rez images.

If this is not an object related to the pterosaur, but coincidentally preserved, then I don’t know what it is. It doesn’t look like familiar animal, plant or mineral material.